I was just at Bald Mountain on the Isle of Mists and a witch had just poured some blood in the water and a creature began to rise and the computer locked up and began making a loud buzzing noise at 100% volume and I had to hit the Reset button on the computer to make it stop.

Is this a known bug?

Don't know yet if it is repeatable. Came to post this before I went back.

No, that's not in the game. Sounds like your PC is overheating...